PONE-D-19-27799

Risk factors and high-risk subgroups of severe acute maternal morbidity in twin pregnancy: a population-based study

PLOS ONE

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Reviewers' comments:

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Comments to the Author

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Reviewer #1: Yes

Reviewer #2: Partly

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: I Don't Know

Reviewer #2: Yes

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Reviewer #1: No

Reviewer #2: Yes

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Reviewer #1: Yes

Reviewer #2: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: This manuscript uses a large population-based study of twin pregnancies "Jumonda" to identify risk factors for severe maternal morbidity and was planned prospectively. The primary outcome was a composite of including maternal death, severe hemorrhage (defined by need for second line therapy), transfusion >=units of pRBCs, uterine artery embolization, and several other severe adverse outcomes. They identified two subgroups of women with a >25% risk of developing severe acute maternal morbidity: those with both oocyte donation, non-severe preeclampsia, and nulliparas born in Sub-Saharan Africa with non-severe preeclampsia.

Reviewer #2: This is a potential wonderful paper. I am afraid I have major problems with the definition of severe morbidity.

Pre ecclampsia requiring delivery is certainly serious but NOT always a severe morbid event.

In a large network Criteria to admit to an ICU will not all be the same and thus potential for bias.

This has the potential for a significant impact please try to find another channel is Tiffany and why except it if I am open even though yours was conducted using a a delfi

Can you be more strict in your defn of SMM and redo ? It will be more meaningful for everyone

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Reviewer #1: No

Reviewer #2: No

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Risk factors and high-risk subgroups of severe acute maternal morbidity in twin pregnancy: a population-based study

PONE-D-19-27799R1

Dear Dr. Korb,

We are pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it complies with all outstanding technical requirements.

Within one week, you will receive an e-mail containing information on the amendments required prior to publication. When all required modifications have been addressed, you will receive a formal acceptance letter and your manuscript will proceed to our production department and be scheduled for publication.

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With kind regards,

Pal Bela Szecsi, M.D. D.M.Sci.

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #2: All comments have been addressed

Reviewer #3: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #2: Yes

Reviewer #3: Yes

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #2: Yes

Reviewer #3: Yes

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4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #2: Yes

Reviewer #3: No

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #2: Yes

Reviewer #3: Yes

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #2: (No Response)

Reviewer #3: Thank you very much for giving me the opportunity to review the revised version of this manuscript.

The current prospective study regards the evaluation of SAMM in twin pregnancy and explore the outcomes identifying relevant subgroups at major risk.

The authors approached the research question correctly from a methodological point of view, defining the so-called basal risk and the subsequent risks that occurred during pregnancy. I think that CART analysis approach and, the subsequent sensitive analysis, represent an optimal approach to the question of the authors. Moreover, the results of the study confirmed a "common-feeling" of increased risk in HRT twin pregnancies.

The authors clearly comment on the strengths and limitations of the study. So far, I agree with the response of the authors regarding the criticism of admissions to ICU and the improbability of a potential selection bias and I agree as well to the other criticism raised and relative responses of the authors.

In my opinion this is a precious paper that has an immediate clinical implication for an active increased surveillance in the subgroups identified.

I have no major concerns on this paper.

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Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #2: No

Reviewer #3: No